1. Field of the Invention
The present invention relates to an apparatus and method for storing and restoring data, and more particularly, to an apparatus and method in which at least one hardware module rapidly reaches a state by using a working context stored in a non-volatile memory.
2. Description of the Related Art
Portable apparatuses such as mobile phones can be used for more time if they have low power consumption. Thus, portable apparatuses in a system-on-a chip (“SOC”) design use a standby mode to reduce power consumption. SOC means that a plurality of systems having independent functions are mounted on one semiconductor chip.
The most common method of reducing power consumption in a standby mode is to cut off a clock signal supplied to all or several circuits of a SOC and reduce the amount of dynamic current consumed by all or several circuits of the SOC. In this case, all or several circuits of the SOC from which the clock signal is cut off do not lose any working context.
However, deep submicron semiconductor devices have currently been designed in the form of a SOC. Since an operating threshold voltage of the SOC decreases, a static leakage current generated in the SOC increases. Thus, the dynamic current consumption and the static leakage current are common problems in portable apparatuses.
Hence, some SOCs use a power-off standby mode, during which power supplied to all or several circuits of the SOCs, which are not needed to be used for a long period of time, is cut off to remove static leakage current generated in the SOCs.
Unfortunately, when the power supplied to the SOCs is cut off, the working context of all or several circuits of the SOCs is lost. When power is supplied again to the all or several circuits of the SOCs, the all or several circuits of the SOCs boot up again. In this case, a long time is required to boot up the circuits, and the all or several circuits of the SOCs do not recover to a state just before the power was cut off.